What is the point of lower or higher bitrates?

GordyHinky wrote on 5/17/2004, 12:17 AM
I've noticed MainConcepts H.264 encoder has a very low bitrate and is comparable in quality to MPEG2 and DV at higher bitrates. Please explain why the lower bitrate matters. Is it just to save disc space? And is that essentially what I'm doing when I lower the bitrate for a DVD...saving disc space? Are there other trade offs?

An unrelated question. What does anyone know about the MainConcept DVCPro 25/50 DV Codec? How is it used and what is required to use it?

Comments

farss wrote on 5/17/2004, 1:22 AM
From memory H.264 is mpeg-4 so you cannot use that on a DVD. I think it's the standard for the next generation of DVB. MPEG-4 uses a much smarter encoding system than mpeg-2 so the same quality can be achieved at a lower bitrate. There are many advantages to being able to use a lower butrate, you can fit more material onto optical media or in the case of broadcast more channels in the same bandwidth. For the same encoding system though in general the lower the bitrate the lower the quality. MPEG-4 I think is mcuh more complex than that though, also the amount of power available in the decoder has an influence on the quality at playback, You'd need to do a fair bit of research to learn all the ins and outs of mpeg-4.
What you have to understand is that there's no point using a particular codec if whoever is going to view the material doesn't have access to it.
DVCPro25/50 is the standard used on most Panasonic cameras. Unless you need to work with matching cameras or VCRs then you can ignore it.
TheHappyFriar wrote on 5/17/2004, 4:36 AM
is there a visible difference between he Matrox DVCPro & the Mainconcept one?

Just wondering if it's worth the cash. :)